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While I am learning Quantum Mechanics with angular momentum and the two types of them:

  • orbital angular momentum

  • and internal angular momentum a.k.a. spin

  • (and total angular momentum, but that is a combined version).

So,

Is there any other types of angular momentum that does not recorded in textbooks or common literature?

PS. I am just talking about angular momentum in general Physics

Qmechanic
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SHY.John
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1 Answers1

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Not really. All angular momenta are either orbital, spin, or a linear combination of the two.

The worst you end up getting is wonky mixtures like these ones, where you mix the spin orbital angular momenta of different shells inside an atom in some weird order, or funky linear combinations of the two (and while we're at this, the photon spin has some tricky behaviour), but they all boil down to those two components.

More generally, there is a meaningful distinction between intrinsic angular momenta $\mathbf L_\mathrm{i}$, which do not change when you displace the origin, and extrinsic angular momenta $\mathbf L_\mathrm{e}$, which transform as $$ \mathbf L_\mathrm e\mapsto \mathbf L_\mathrm e'=\mathbf L_e-\mathbf r_0\times\mathbf P $$ when you displace the system as $\mathbf r\mapsto \mathbf r'=\mathbf r-\mathbf r_0$, and where $\mathbf P$ is the total angular momentum of the system. As regards your question, though, they are just descriptors that apply respectively to spin and orbital angular momenta.

Emilio Pisanty
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